1. Technical Field
This disclosure generally relates to computer systems, and more specifically relates to managing capacity on demand with multiple servers in a server cloud.
2. Background Art
One problem with computer systems today is balancing the cost of the computer hardware with fluctuating demands on computer resources. In most networked computer systems, there are times when the computing demands are relatively low, and other times when the computing demands are very high. If a company purchases a computer system that is capable of meeting peak demand, much of the capacity of the computer system will go unused during non-peak times. In addition, purchasing capacity to meet peak demand is costly. If a company purchases a computer system that is capable of meeting average demand, the cost is lower, but the performance of the computer system suffers during peak times.
One way to provide a more flexible solution allows a computer user to buy a computer system that has some resources installed, but initially disabled. When the customer determines that more capacity is needed, the customer may enter into an arrangement with the provider of the computer system to enable certain resources for a fixed period of time. This works out particularly well for companies that have seasonal peaks. The companies can purchase a computer system at a reasonable cost that has the capability of providing enhanced computing power during the peak season. The ability to purchase additional capacity when needed is known as Capacity On Demand.
A simple example will illustrate. Let's assume that a company that sells goods via catalog sales experiences peak demand in November and December of each year due to holiday shopping. The company could purchase a computer system that has one or more additional processors that are installed but initially disabled. The company may then contract with the provider of the computer system to enable the additional processor(s) for a set period of time. Let's assume that the computer system has two additional processors, and let's assume that the peak buying period runs for the thirty day period from November 15th to December 14th. The customer could purchase sixty processor-days of additional capacity beginning on November 15th. These two additional processors will then be enabled for the thirty day period (providing the sixty processor-days of additional capacity). Once the sixty processor-days have elapsed, the two additional processors are disabled.
Sever clouds allow different server computer systems to work together. Each server may have additional resources (such as processors, memory, etc.) that are installed but not enabled, but may be enabled as needed on a Capacity On Demand basis. However, even though the servers in a cloud may communicate and cooperate in processing a job, the Capacity On Demand capabilities of each server are separate and distinct from all other servers. Thus, if a server has a compute-intensive job to process and needs additional processor capacity, it does so in a manner based on its own available processor capacity, without regard to the other servers in the server cloud.